Balanced flue enclosed infra-red heater



March 25, 1969 P, H|NE, JR I 3,434,466

BALANCED FLUE ENCLOSED INFRA-RED HEATER I Filed May 31, 1967 Sheet of 3 F|G.2. 2| I 25 I 7 zv i J 28 i I i 1 WITNESSES INVENTOR ZZZ-D1414 Louis F? Hine,Jr.

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March 25, 1969 L. P. HINE, JR 3,434,466

BALANCED FLUE ENCLOSED INFRA-RED HEATER Filed May 51, 1967 Sheet 2 of s m T T F I G. 3.

March 25, 1969 P. HINE. JR 3,434,466

BALANCED FLUE ENCLOSED INFRA-RED HEATER Filed May 31, 1967 Sheet 9 of s United States Patent 0.

3,434,466 BALANCED FLUE ENCLOSED lNFRA-RED HEATER Louis P. Hine, Jr., Elyria, Ohio, assignor to Luxaire, Inc., Elyria, Ohio, a corporation of Delaware Filed May 31, 1967, Ser. No. 642,475 Int. Cl. F24c 3/04; F23d 13/14 US. Cl. 126-92 Claims ABSTRACT OF THE DISCLOSURE Background of the invention This invention relates to an enclosed draft resistant infra-red heater.

Infra-red radiant space heaters are well known for spot-heating localized areas. Both gas and electric forms of such heaters are used and in many applications the gas-fired heater may be preferred for reasons of economy. Most applications of such heaters are in relatively sheltered locations so that they are not subjected to unusual air pressure differentials. It has been proposed to mount a gas-fired infra-red heater in the roof of a relatively unenclosed passenger shelter for a transportation system and under such circumstances it has been found that the heater may be subject to unusual wind pressure differentials causing the heaters to roll down and shoot flames into the shelter and frighten the passengers or to fail to function altogether. In order to completely enclose and shelter the infra-red heater from such differential air pressures, the problems of supplying combustion air and exhausting exhaust gas products of combustion under controlled conditions while permitting infra-red radiation to be emitted must be solved.

Prior art Gas-fired infra-red radiant heaters are disclosed by the following listed patents although none of these patents disclose a completely enclosed draft-resistant arrangement as will be described for the present invention. 3,225,815, Bauer et al., Dec. 28, 1965; 3,203,413, Hartzell et al., Aug. 31, 1965; 3,173,470, Wright, March 16, 1965.

These patents are classified in class 158 subclass 99 and class 126 subclass 92 of the official United States Patent Ofiice classification.

Summary In accordance with the invention, a heater housing having upper, lower, side and end walls is provided with a window in the lower wall closed with infra-red transmissive material such as quartz or the like. Disposed within the housing is an infra-red burner with its radiant surface spaced from but opposite the window in the lower wall of the housing. The upper wall of the housing is provided with a pair of substantially identical hooded openings having smaller opening areas and being closely spaced and substantially parallel to each other so that differential air pressures over the upper heater wall will affect both openings substantially uniformly. An exhaust stack from one side of the burner extends through one of said openings and the cross-sectional area of the stack 3,434,466 Patented Mar. 25, 1969 is less than the cross-section area of the opening through which it extends. Combustion air and cooling air is drawn in through the other opening and the spaces between the exhaust stack and the opening through which it extends. In a preferred form of the invention the burner is mounted with its radiant surface inclined towards the side adjacent the exhaust stack so that combustion products will flow more readily into the stack. Also, in a preferred form of the invention, the heater housing is enclosed in an outer surrounding protective housing having a screened lower opening spaced from the infra-red radiant window to protect the window from foreign objects and in addition the outer housing may be provided with one or more ventilation openings to enable a flow of cooling air around the side walls of the enclosed heater housing. Further objects, features and the attendant advantages of the invention will be apparent with reference to the following specification and drawings.

Brief description of the drawings FIGURE 1 is a perspective elevation partly broken away of the enclosed radiant heater of the invention as seen from below;

FIG. 2 is a top plan view of the invention;

FIG. 3 is a section taken generally on the line IIIIII of FIG. 4 with the top closure panel for the heater housing removed;

FIG. 4 is a section taken along the line IV-IV of FIG. 3 with some parts broken away for clarity;

FIG. 5 is a section taken on the line V-V of FIG. 3; and

FIG. 6 is a section taken on the line VI-VI of FIG. 3.

Description of the preferred embodiment of the invention Referring to the drawings, an infra-red heater having a burner casting 10 with a venturi opening 11 and a burner gas nozzle 12 together with a radiant burning screen 13 and an outer reverberator screen 14 is mounted within a heater enclosure or housing generally shown at 15. The heater housing 15 is comprised of side walls 16 and 17, end walls 18 and 19, a lower Wall 20 and an upper wall 21. The lower wall 20 is provided with a window closed by an infra-red transmissive material such as quartz 22 although any suitable infra-red transmissive material may be used. It will be noted that the infra-red generating heater surface 13 of the infra-red burner is spaced above but generally opposite the infra-red transmissive window 22 of the heater housing 15 so that infra-red radiation from the screen 13 may be passed through the window 22 downward onto the desired area or spot to be heated. It should be understood that this invention is not limited to a wire screen burning surface 13 but that other forms of burner surfaces such as a ceramic surface may be used.

As is more clearly shown by FIGS. 2, 5 and 6 of the drawings, the upper wall 21 of the heater housing is provided with a pair of openings 25 and 26 having substantially identical opening areas and closely spaced to each other in a generally parallel arrangement. Weather hoods 27 and 28 are mounted over the respective openings 25 and 26 to prevent rain and foreign objects from entering such openings. Input combustion air passes through the opening 25 into the interior of the burner housing 15 where it may be drawn in the direction of the arrow shown by FIG. 4 into the venturi 1-1 of the burner casting 10 and mixed with gas from the nozzle 12 for ignition on the radiant surface 13. It is a very important feature of the invention that both of the openings 25 and 26 are substantially identical in area and are closely spaced to each other so that differential air pressures occurring over the top surface 21 of the enclosure affect similarly 3 both the inlet opening 25 and the opening 26 through which the exhaust stack 30 extends.

As just mentioned, an exhaust stack 30 extends from one side of the infra-red burner 10 through the opening 26 in the top wall 21 of the heater housing. It will be noted that the exhaust stack 30 is of less cross-sectional area than the opening 26 so as to provide the requisite flue action for drawing out the products of combustion from the burner surface 13. Since the exhaust stack 30 is of less cross-sectional area than the opening 26 through which it extends, additional combustion air may flow in through the spaces between the exhaust stack 30 and the side walls of the opening 26 and balanced conditions under varying pressure differentials are obtained.

In the preferred form of the invention the heater 10 is mounted as more clearly shown by FIGS. and 6 of the drawings with its radiant surface 13 inclined in the direction of the exhaust stack 30 so that the products of combustion will tend to flow more readily to and through the elongated opening 29 to the exhaust stack 30. Also, as more clearly shown by FIGS. 3 and 6 of the drawings, at one end of the exhaust stack 30, namely the end closest to the gas nozzle 12 of the burner 10, a pilot chamber 31 is provided. This pilot chamber is completely sealed by the wall surfaces 32-37 from the outside air so as to be part of the heater enclosure and completely within the heater enclosure. Air from within the heater enclosure 15 passes through the lower opening 41 of the pilot flue 31 to be ignited with the gas from the pilot nozzle 42 for lighting the main radiant burner surface 13 through opening 43. The details of the free standing gas pilot 42 are not shown since they are well known to those skilled in the art and may take various forms, and in fact any suitable pilot arrangement elec trically controlled or otherwise may be placed within the pilot stack 31 in the heater enclosure.

In order to protect the enclosed infra-red burner and its infra-red transmissive window 22 from external foreign objects the heater housing 15 may be enclosed in an outer surrounding housing comprising side and end walls 50-53, and a lower screened opening 55. The inclined lower walls 56-59 project upward from the lower screened opening 55 to the infra-red transmissive window 22 of the heater housing 15. One or more ventilation openings such as the opening 60 may be provided to allow air flow between the side walls 50-53 and the side and end walls of the heater housing 15 for purposes of cooling the side walls of .the heater housing. The upper wall closure 21 of the heater housing is extended as shown at 62 and 63, 64 and 65 to provide an overhang for weather protection together with a vent for the cooling air flow between the walls of the inner and outer housings.

Various modifications will occur to those skilled in the art to provide for different forms of radiant heater enclosures while still using the principles ot the invention in the provision of a pair of closely spaced substantially identical openings for the heater housing enclosure through which are passed the combustion air and products of combustion pass to be effected substantially uniformly by differentials in air pressure occuring over the heater housing.

I claim as my invention:

1. An enclosed draft resistant infra-red heater comprising, a heater housing having upper, lower, side, and end walls, a window closed with an infra-red transmissive material in said lower wall, an infra-red gas burner assembly mounted within said heater housing with a surface adapted to emit infra-red radiation spaced above and opposite said window, a pair of hooded and closely spaced openings in the upper wall of said housing above said burner, and an exhaust gas stack extending from one side of said burner through one of said openings, the cross-sectional area of said stack being less than the area of the opening through which it extends, said burner assembly having means to receive combustion air from said openings via the space within said housing, both of said openings having substantially the same area so that variations in air pressures flowing over said upper wall effect both openings substantially uniformly.

2. The invention of claim 1 in which said openings are elongated and positioned substantially parallel to each other.

3. The invention of claim 1 in which said burner assembly is mounted within said housing in a manner to incline the radiating surface upwards toward the side adjacent the exhaust stack to direct the products of combustion towards the exhaust stack.

4. The invention of claim 1 in which said heater housing is enclosed in an outer surrounding protective housing with a screened lower opening spaced from the lower window opening of the heater housing, and one or more ventilation openings are provided in the walls of the outer housing to provide cooling air flow for the side walls of the heater housing.

5. The invention of claim 3 in which said heater housing is enclosed in an outer surrounding protective housing with a screened lower opening spaced from the lower window opening of the heater housing, and one or more ventilation openings are provided in the walls of the outer housing to provide cooling air flow for the side walls of the heater housing.

References Cited UNITED STATES PATENTS 2,422,694 6/ 1947 McCollum. 2,759,472 8/ 1956 Cartter. 2,936,751 5/1960 Porniti. 3,291 ,1 15 12/ 1966 Forniti. 3,307,529 3/1967 Fannon et a1. 3,315,656 4/ 1967 Eichenlaub.

JAMES W. WESTHAVER, Primary Examiner.

US. Cl. X.R. 43 1329 

